An exhaust gas flap drive is already known from DE 10 2009 016 597 B4. This has a coupling spring, via which the motor shaft is coupled to the exhaust gas flap shaft. A clip holder is provided on the motor shaft which serves to retain or affix the coupling spring on the end side.
An exhaust gas flap drive is known from U.S. Pat. No. 7,374,147 B2 in which the flap shaft is connected via a first coupling spring with a coupling disc, wherein the coupling disc is coupled via a second coupling spring to the housing. In both cases, the coupling disc is in a form fit with the respective coupling spring in the circumferential direction via a groove or a pin. The second coupling spring also has in the axial direction an at least single-sided form fit with the hook-shaped pin of the coupling disc.
DE 41 31 502 A1 describes a valve flap with a valve axis, which is directly driven by a pulley. A return spring is arranged at each end of the valve axis. The lower return spring is suspended in a groove of the bush and has a non-backlash-free form fit in the axial direction and in a circumferential direction.
Additionally, an exhaust gas flap drive is known from EP 1 887 200 A1. This has a flat coupling spring, via which the motor shaft is coupled to the exhaust gas flap shaft. A slit holder is provided on the exhaust gas flap shaft, which serves to retain in a torque-free manner or affix the coupling spring.